Door closure device



0e48, 1968 J, R. JOHNSTON 3,404,426

DOOR CLOSURE DEVICE Filed April 17, 1967 4 Sheets-Sheet 1 INVENTOR.

JAMES R. JOHNSTON BY 7/24 M ATTORNEY! Oct. 8, 1968 J. R; JOHNS TON 3,404,426

DOOR CLOSURE DEVICE Filed April 17, 19s? v 4 Sheets-Sheet. 2

FIG. 2

' INVENTOR.

70 62 v JAMES R. JOHNSTON ATTORNEY Oct. 8, 1968 J. JOHNSTON DOOR CLOSURE DEVICE 4 Sheets-Sheet 5 Filed April 17, 1967 IFIIG.I3'

INVENTOR.

JAMES R. JOHNSTON BY ATTORNEY 1968 J. R. JOHNSTON 3,404,426 1 DOOR CLOSURE DEVICE Filed April 17, 1967 4 Sheets-Sheet 4 FIG. IO

I N VEN TOR. JAMES R. JOHNSTON ATTORNEY United States Patent Office 3,404,426 Patented Oct. 8, 1968 3,404,426 DOOR CLOSURE DEVICE James R. Johnston, Elkhart, Ind., assignor to Ridge Products, Inc., Elkhart, Ind., a corporation of Michigan Filed Apr. 17, 1967, Ser. No. 631,545 14 Claims. (Cl. 16-51) ABSTRACT OF THE DISCLOSURE A door closure device having a cylindrically shaped housing and a cylindrically shaped rotor disposed in the housing for rotation therein and a spring in the rotor interconnecting the housing and the rotor. The rotor is connected by an axial shaft to a link for operating the closure device, and a fluid chamber is disposed around the external wall of the rotor for a viscous fluid which retards or dampens the closing movement of the door effected by the torsion action of the coil spring.

In conventional door closing mechanisms utilizing the damping principle, a relatively large volume of fluid is trapped as the door is opened and is metered as the door is closed to provide the desired closing rate and control of the door. The fluid is permitted by one or more valve means to flow freely while the door is being opened, and is retained under substantial pressure during the door closing operation, during which time the fluid is metered through a fixed or variable orifice to give the desired door closing rate. Because of the high pressure and normally low viscosity of the fluid, the unit must be effectively sealed to avoid leakage and to obtain satisfactory performance. The housing for the fluid must necessarily be relatively strong and bulky, often causing diflicult installation problems and excessive costs. Further, the prior door closing mechanism involved a number of relatively small movable and/or adjustable parts which, along with the high fluid pressure condition existing in the unit during certain states of operation, made the mechanism inherently relatively difficult and expensive to fabricate. More recently a viscous fluid type door closure has replaced the aforementioned pressure fluid type in variou fields and, while these have given satisfactory performance, they have involved the use of relatively expensive parts in order to obtain optimum performance. It is therefore one of the principal objects of the invention to provide a door closure of the viscous fluid type which is simple and compact in construction, requiring only relatively broad tolerances in materials and dimensions and which will perform satisfactorily under all Weather and operating conditions.

Another object of the invention is to provide a door closing device which is constructed of easily fabricated parts of simple design and which is easily adapted to various types of doors and door installations and will thereafter give long trouble-free service without periodic adjustment or other attention.

Still another object of the invention is to provide a highly reliable and rugged door closing mechanism of the viscous fluid type in which control of the door opening and closing operations is obtained primarily by the shear action of a small volume of fluid under low pressure and in which the reaction parts are maintained by the fluid in a substantially balanced condition.

A further object is to provide a door closing mechanism of the aforesaid type which gives controlled door action throughout the door opening and closing operations by a pre-set performance pattern, and which applies a positive force to latch the door as the final door closing movement is completed.

Additional objects and advantages of the invention will become apparent from the following description and accompanying drawings, wherein:

FIGURE 1 is a perspective view of the present closure showing it mounted on a door and connected to the upper member of the door frame;

FIGURE 2 is a vertical cross-sectional view through the primary operating mechanism of the present door closure;

FIGURE 3 is a horizontal cross-sectional view of the closure shown in FIGURE 2, the section being taken on line 3-3 of the latter figure;

FIGURE 4 is an elevational view of the primary spring used in the closure of the preceding figures;

FIGURE 5 is an end view of the spring shown in FIG- URE 4;

FIGURE 6 is an elevational view of a cylindrical rotor incorporated in the present closure;

FIGURE 7 is a top plan view of the rotor shown in FIGURE 6;

FIGURE 8 is a front elevational view of the casing of the present closure;

FIGURE 9 is a top plan view of the casing shown in FIGURE 8;

FIGURE 10 is a side elevational view of the housing in which the rotor is mounted; and

FIGURE 11 is a top plan view of the housing shown in FIGURE 10, the housing shown in the condition before it is assembled in the casing.

Referring more specifically to the drawings and to FIGURE 1 in particular, numeral 10 designates generally the present door closing device, 12 the primary operating mechanism, 14 a casing in which the primary mechanism is disposed and which is mounted on and. securely attached directly to door 16, and numeral 18 indicates a link connected at one end to the primary operating mechanism and at the other end to the door frame indicated generally by numeral 20. In the installation shown in FIG- URE 1, the door is mounted on a plurality of hinges 22 attached to the door frame; however, the present door closure may be used satisfactorily with various types of doors and door installations, of both the right and left hand opening type, without modification of the primary closure mechanism.

A cylindrical housing or stator 30 is mounted in casing 14 and is rigidly supported therein in close proximity to the front wall 32 and side walls 34 and 36 by top plate 38 which is rigidly connected to the backing plate 39 of the casing and when assembled in the casing, is in firm contact with the upper edges of the front and two side walls. The housing is provided with a plurality of upwardly extending ears 40 which extend through a. plurality of arcuate slots 42. The ears are rolled laterally inwardly on the top side of top plate 38, thus securely retaining the housing in fixed position in the casing. The housing is assembled in this manner after the internal mechanism thereof has been assembled in operating position in the housing. When the housing has been assembled in the casing in the foregoing manner, it is supported rigidily by the casing which, in turn, is securely attached to the door by a plurality of screws 44 extending through flanges 46 and 47 and through the backing plate 39 on each side of the casing. The top plate is formed integrally with the backing plate, which is held rigidly on the door, along with the front of the casing, by screws 44. When housing 30 is assembled in the casing, it is suspended from top plate 38 and is prevented from rotating or otherwise moving in the housing by the overturned ears 40 extending through slots 42. Rotor 60, which is preferably made of plastic material such as acetal resin, referred to in the trade as Delrin, is rot-atably mounted in housing 30 and is in contact with the bottom 62 of the housing and in spaced relation to the internal side wall of the housing, thus providing an annular chamber 64 extending fully around the external wall of the rotor. A shaft- 66 of hexagonal cross-section extends vertically through the rotor and is seated in a hexagonal recess 67 in a boss 68 on the internal surface of rotor bottom 70 for rotation with the rotor. The shaft extends through a hole 72 in top plate 38 and is connected to one end of link 18 which is rigidly secured to the upper end of the shaft by a nut 74 threadedly received on the shaft. A heavy coil main spring 80 is disposed in the rotor and connected to the bottom thereof by an inwardly extending end 82 seating in a slot 84 formed by web members 86 and 88 extending radially from boss 68. The two members 86 and 88 prevent relative rotation between the lower end of the spring and the rotor. The upper end of the spring is operatively connected to an upper end plate 90 which seats on the upper end of the housing and has outwardly extending peripheral bosses 92 projecting into the slot between ears 40. Thus when the housing 30 is assembled on the underside of top plate 38 with ears 40 extending upwardly through slots 42, the upper end plate 90 is held rigidly in place between the upper end of the housing and plate 38. The underside of upper plate 90 is provided with two downwardly extending lugs 94 and 96 into which an inwardly projecting upper end 98 of spring 80 is seated; thus the lugs hold the upper end of the spring against relative rotation with the plate 90. With the lower end of the spring operatively attached to rotor 60 and the upper end of the spring operatively connected to upper end plate 90 and hence to housing 30, angular movement of link 18, shaft 66 and rotor 60 causes spring 80 to coil or uncoil, and thereby places tension on the spring, which is utilized to close the door.

Link 18 consists of two arms 100 and 102 pivotally connected to one another by a pin 104. The inner end of arm 100 is held rigidly on shaft 66 by nut 74, and the inner end of arm 102 is pivotally attached to the upper member of the door frame by a bracket 106 and bolt 108. Movement of the door in the opening direction causes shaft 66 to rotate, thereby placing tension on spring 80, creating a potential force in the spring for closing the door as soon as it is released. A plastic sleeve 110 is inserted over shaft 66 at the upper end thereof, and includes an extension 112 projecting downwardly through hole 72 in top plate 38 and hole 114 in upper end plate 90, and forming a bearing surface for engagement with flange 116 on plate 90. The shaft is held in place in the rotor by a snap ring 118 seating in annular groove 119 in the shaft and abutting the lower end of flange 116.

Chamber 64 contains a fluid of relatively high viscosity and, in order to effectively control the closing operation of the door by the relative rotation of the internal wall of housing 30 and the external wall of rotor 60, two internal vertically positioned ribs 120 and 122 are provided on the internal surface of the housing wall and two vertically positioned ribs 124 and 126 are provided on the external surface of rotor 60. The two internal ribs on the housing and the two external ribs on the rotor are positioned diametrically opposite one another on the respective parts. The ribs on the housing and those on the rotor are closely spaced to one another, thereby forming restrictions 128 and 130 which retard the flow of the viscous fluid from one side of each cooperating pair of ribs to the other, the ribs forming in effect a shearing action on the fluid which dampens and retards the closing action of the door. At different stages of the door opening and closing operation, when the ribs on the housing and rotor are separated, the viscosity of the fluid primarily performs the dampening or retarding function; however, when the cooperating ribs on the housing and cylinder approach one another and/or are positioned radially from one another, the shearing action is dominant, causing a further temporary delaying or dwelling action in the door closing operation.

The fluid in chamber 64 is preferably a silicone having a viscosity of between about 60,000 to 1,000,000 centistokes and having a substantially constant viscosity ternperature ratio between about 0 and 100 C. A more limited preferred range is 400,000 to 700,000 centistokes. The rate at which the door closes can be predetermined by selecting a fluid with the proper viscosity, and selecting a main spring with the proper torsional rate, for a given distance between the rotor and housing walls forming chamber 64. The fluid is sealed in the chamber by an annular gasket 136 seated in a groove 138 at the upper edge of rotor 60, thereby sealing the space between the rotor and the internal wall of the housing at the upper edge thereof to form a completely closed chamber for the fluid, thus eliminating the need for refilling or replacing the fluid from time to time during the operation of the closure. The chamber is sealed at the bottom by direct contact between the bottom of the rotor and the bottom of the housing.

In the operation of the present closure installed in the manner illustrated in FIGURE 1, opening the door 16 causes angular movement of arm 100 of link 18 and clockwise rotation of shaft 66 and rotor 60, as viewed in FIGURE 3. Since the lower end of spring is operatively connected to the lower end of the rotor, and since the upper end of the spring is anchored to plate 90, which in turn is anchored, along with the housing, to backing plate 39, a torsional force is applied to the spring, causing it to coil. After the door has been opened and released, the force in the coiled spring urges the rotor in the counterclockwise direction, as viewed in FIGURE 3, rotating shaft 66 and moving arm in the counterclockwise direction, thus moving the door toward closed position. The viscous fluid in chamber 64 permits relatively rapid rotation of the rotor in the housing, until the matching operating ribs and 124 and 122 and 126 approach one another, at which time the shearing action of the fluid dominates, causing a distinct retarding effect in the door closing action. As soon as the cooperating ribs pass one another, the action of the viscous fluid still retards the closing action but permits a more rapid closing movement until the door is closed. Since some tension is maintained on the coil spring when the door is closed or substantially closed, a positive locking of the door is obtained.

It is seen from the foregoing description that the present closure requires no adjustments and virtually no service after installation has been made. The closure applies a constant closing force on the door, while at the same time it prevents objectionable, rapid closing at any point in the movement of the door. Variations in the movement of the door from one installation to another may be obtained by varying the position of the vertical ribs on the internal side wall of the housing and on the external side wall of the rotor, and a distinct dwell may be obtained shortly before the door is fully closed to permit the door to shut gently.

The simplicity of the parts forming the present device and the wide permissible tolerances permit a number of the metal parts, such as the housing, casing and end plates, to be made as metal stampings, thus materially reducing the cost of the device. Further, the retarding action of the fluid in chamber 64 can be readily adjusted to compensate for tolerance variation by selecting a fluid of the proper viscosity. The chamber between the rotor and housing is sufficiently narrow and the fluid sufficiently viscous that a substantial retarding action is imparted to the door irrespective of the position of the ribs relative to on another.

The present device is designed primarily for use in controlling the operation of doors; however, it can be used satisfactorily in various other applications requiring a damping action, such as for example, lids and other closures. When the device is referred to herein as a door closure device, it is intended to include the device when I drical housing, a generally cylindrical rotor mounted in said housing and having a hollow interior, an axially positioned shaft disposed in said rotor and extending from the end thereof, a link connected to said shaft for controlling the closing movement of a door, a coil spring disposed in the hollow interior of said rotor and being operatively connected at one end to said rotor and at the other end to said housing, a chamber between the external wall of said rotor and the internal wall of said housing, a viscous fluid in said chamber, a pair of cooperating longitudinally positioned ribs on the external and internal walls of said rotor and housing, respectively, for producing a shearing action on the fluid in said chamber to retard the relative rotation between said rotor and housing, and a support means for rigidly mounting said housing on a door member.

2. A door closure device as defined in claim 1, in which the lower end of said coil spring is operatively connected to the bottom of said rotor, and the upper end of said spring is connected to the upper end of said housing.

3. A door closure device as defined in claim 1, in which said cylindrical rotor is formed of plastic material and in which the lower end of said rotor seats on the internal lower end of said housing.

4. A door closure device as defined in claim 1, in which the fluid in said chamber is silicone having a viscosity of between about 60,000 and 1,000,000 centistokes.

5. A door closure device as defined in claim 4, in which the fluid in said chamber is silicone having a viscosity of between about 400,000 and 700,000 centistokes.

6. A door closing device as defined in claim 1, in which two pairs of Cooperating longitudinally positioned ribs are provided on the external and internal walls of the rotor and housing, respectively.

7. A door closing device as defined in claim 3, in which two pairs of cooperating longitudinally positioned ribs are provided on the external and internal walls of the rotor and housing, respectively.

8. A door closing device as defined in claim 7, in which said tWo pairs of ribs are disposed diametrically opposite to one another in said fluid chamber.

9. A door closing device as defined in claim 7, in which said two pairs of ribs are disposed diametrically opposite to one another in said fluid chamber.

10. A door closure device as defined in claim 1, in

which a casing having a backing plate is provided for supporting said housing in fixed position and for mounting the device on a door.

11. A door closing device as defined in claim 9 in which a top plate of the casing is formed integrally with the backing plate and is provided with slots therethrough, and in which said housing is provided with ears at its upper edge for seating in said slots and thereby to secure said housing to said top plate.

12. A door closure device as defined in claim 4, in which two pairs of cooperating longitudinally positioned ribs are provided on the external and internal walls of the rotor and housing, respectively.

13. A door closure device as defined in claim 5, in which two pairs of cooperating longitudinally positioned ribs are provided on the external and internal walls of the rotor and housing, respectively.

14. A door closure device as defined in claim 1, in which the chamber between the rotor and housing is sufficiently narrow and the fluid sufiiciently viscous that a substantial retarding action is imparted to the door irrespective of the position of the ribs relative to one another.

References Cited UNITED STATES PATENTS 3,316,582 5/1967 Johnston et al. 16-51 BOBBY R. GAY, Primary Examiner.

I. L. KOHNEN, Assistant Examiner. 

